1. Field
Apparatuses and methods consistent with exemplary embodiments relate to splitting a light incident onto an image sensor to separate color of the light.
2. Description of the Related Art
A color image sensor detects a color of light incident thereon via a color filter. The color image sensor may, for example, use a red green blue RGB color filter method. According to this method, green filters are arranged in two pixels and a blue filter and a red filter are respectively arranged in the remaining pixels in a pixel unit including four pixels. Except the RGB color filter method, a cyan yellow green magenta CYGM color filter method may also be used. In this case, color filters of cyan, yellow, green and magenta, which are complementary colors, are respectively arranged in four pixels.
However, the color filter may reduce the light utilization efficiency because lights of all colors except the corresponding color light are absorbed. For example, when the RGB color filter is used, since only one third of the incident light is transmitted and the remaining two thirds are absorbed, the light utilization efficiency may be as low as about 33%. Thus, in the color image sensor, most of the light loss occurs in the color filter.
Recently, attempts to use a color splitter have been made to improve the light utilization efficiency of the color image sensor. The color splitter may separate colors of light incident thereon according to a characteristic that diffraction or refraction of light is different depending on the wavelength of light. Colors separated by using the color splitter may be respectively transferred to corresponding pixels. Accordingly, the light utilization efficiency of the color image sensor may be improved when the color splitter is used, compared with a case when only the color filter is used.